Error Measurement Between Anatomical Porcine Spine, CT Images, and 3D Printing.

RATIONALE AND OBJECTIVES: 3D printers are increasingly used in medical applications such as surgical planning, creation of implants and prostheses, and medical education. For the creation of reliable 3D printed models of the vertebral column, processing must be performed on CT images. This processing must be assessed and validated so that any error of the printed model can be recognized and minimized. MATERIAL AND METHODS: In order to perform this validation, 10 CT scans of porcine lumbar spinal vertebra were used, which were then dissected and scanned again. CT image processing was performed to obtain a mesh and perform 3D printing. RESULTS: There was no statistical difference among the four different levels of vertebrae measurements (first CT images, second CT images, anatomical piece of porcine bone and 3D printing of porcine bone; One Way repeated measure ANOVA, F < F_crit, p value > α = 0.05). The Intraclass Correlation also revealed a mean intraclass correlation coefficient (3,1) = 0.9553, which describes the reliability of all four levels in addition to the reliability of the data between porcine samples subjected to different levels of measurement. This shows that the average error is less than 1 mm. CONCLUSIONS: The measurements of models created with 3D printers using the pipeline described in this paper have an average error of 0.60 mm with CT images and 0.73 mm with anatomical piece. Thus, 3D printed models accurately reflect in vivo bones and provide accurate 3D impressions to assist in surgical planning.

Visual analysis of automated segmentation in the diagnosis of focal cortical dysplasias with magnetic resonance imaging.

Focal cortical dysplasias (FCDs) are a frequent cause of epilepsy. It has been reported that up to 40% of them cannot be visualized with conventional magnetic resonance imaging (MRI). The main objective of this work was to evaluate by means of a retrospective descriptive observational study whether the automated brain segmentation is useful for detecting FCD. One hundred and fifty-five patients, who underwent surgery between the years 2009 and 2016, were reviewed. Twenty patients with FCD confirmed by histology and a preoperative segmentation study, with ages ranging from 3 to 43 years (14 men), were analyzed. Three expert neuroradiologists visually analyzed conventional and advanced MRI with automated segmentation. They were classified into positive and negative concerning visualization of FCD by consensus. Of the 20 patients evaluated with conventional MRI, 12 were positive for FCD. Of the negative studies for FCD with conventional MRI, 2 (25%) were positive when they were analyzed with automated segmentation. In 13 of the 20 patients (with positive segmentation for FCD), cortical thickening was observed in 5 (38.5%), while pseudothickening was observed in the rest of patients (8, 61.5%) in the anatomical region of the brain corresponding to the dysplasia. This work demonstrated that automated brain segmentation helps to increase detection of FCDs that are unable to be visualized in conventional MRI images.

Terapia continua intra-arterial selectiva con nimodipino para el tratamiento del vasoespasmo refractario en hemorragia subaracnoidea aneurismática: caso clínico / Continuous intra arterial nimodipine for vasospasm secondary to subarachnoid hemorrhage: report of one case

We report a 39-year-old male with an aneurysmal subarachnoid hemorrhage without hydrocephalus, in whom a right choroidal aneurysm was early excluded by endovascular coil insertion. Intracranial pressure (PIC) and cerebral oxygenation (PtiO2) sensors for neuromonitoring were installed due to a persistent comatose state. From the 3rd day, neuromonitoring became altered. CT angiography and cerebral angiography showed severe proximal and distal vasospasm (VE) of the middle (ACM) and anterior (ACA) right cerebral arteries. VE was treated with angioplasty and intravenous nimodipine. Forty eight hours later, despite hemodynamic maximization, neuromonitoring became altered again, mainly explained by a decrease in PtiO2 below 15 mmHg. A severe VE in ACM and right ACA was confirmed by angiography. Given the presence of an early and recurrent VE, which was associated with a decrease in cerebral oxygenation, internal carotid micro-catheters for continuous nimodipine infusion were installed. This therapy maintained a normal neuromonitoring for 15 days. During this period, attempts were done to decrease or discontinue the infusion, but the patient presented parallel falls of cerebral oxygenation or decreased cerebral perfusion observed with perfusion CT, interpreted as persistent VE. Finally, the infusion was stopped at day 15 without significant complication. We conclude that intra-arterial nimodipine continuous infusion in refractory VE can be useful and safe in selected patients. Multimodal neuromonitoring is essential.

Otitis media and mastoiditis in temporal bones of prehistoric Chilean populations. A paleopathological and paleoepidemiological study.

BACKGROUND: This study evaluates otitis media in prehistoric populations in northern Chile. AIMS/OBJECTIVES: Determining prevalence of otitis media and diagnostic usefulness of temporal-bone X-rays in skulls. MATERIALS AND METHODS: 444 skulls belonging to three groups: prehistoric-coastal (400-1000 AD), prehistoric-highland (400-1000 AD) and Pisagua-Regional Developments (1000-1450 AD). Skulls were evaluated visually and with Schuller's view X-rays. Five skulls diagnosed as having had otitis media, five diagnosed as normal, and one with temporal bone fistula also had a computed tomography (CT). RESULTS: Changes suggestive of otitis media were present in Prehistoric-coastal 53.57%; Pisagua-Regional Developments 70.73%; prehistoric-highlands 47.90%. Diagnostic effectiveness of Schuller's view X-rays for assesing middle ear disease was confirmed by CT studies. The case with temporal bone fistula had changes suggestive of mastoiditis and possible post auricular abscess. CONCLUSIONS: There was a high prevalence of otitis media in prehistoric populations in Chile. The higher prevalence in one group was presumably due to racial factors. Temporal-bone X-rays are effective for massive evaluation of ear disease in skulls. A case of mastoiditis with temporal bone fistula and possible post-auricular abscess is documented. SIGNIFICANCE: Documenting racial factors in otitis media. Validating X-rays for massive evaluation of otitis media in skulls.

Mastoid osteoma in a prehispanic cranium (1390 A.D.) from Northern Chile.

OBJECTIVE: Osteomas are slow-growing benign tumors that can affect the skull, most frequently the parietal and frontal. Temporal bone osteomas are more common in the external acoustic meatus and exceptional in the mastoid region. The rarity of mastoid osteomas is confirmed by the fact that very few cases have been reported in the clinical and paleopathological literature. The aim of this paper is to report a new paleopathological case of mastoid tumor in a Pre-Hispanic adult cranium. MATERIALS: The skull derives from the Chunchuri (today Dupont-1 site) Pre-Hispanic site in Northern Chile (1390 A.D). METHODS: Macroscopical examination and high-resolution tomography were used to assess the cranium. RESULTS: The CT scan revealed a well demarcated lesion suggestive of a mastoid osteoma. CONCLUSIONS: This case adds new evidence regarding the antiquity of primary neoplasms in ancient populations and reinforces the importance of high resolution imaging in paleopathological research. SIGNIFICANCE: Due to the antiquity of the remains this is probably the oldest reported case of mastoid osteoma. LIMITATIONS: The patrimonial nature of the remains did not allow histopathological studies. SUGGESTIONS FOR FURTHER RESEARCH: Further intensive review of archeological skeletal collections is needed to better understand the epidemiology of neoplastic lesions in past populations.

[Continuous intra arterial nimodipine for vasospasm secondary to subarachnoid hemorrhage. Report of one case]. / Terapia continua intra-arterial selectiva con nimodipino para el tratamiento del vasoespasmo refractario en hemorragia subaracnoidea aneurismática. Caso clínico.

We report a 39-year-old male with an aneurysmal subarachnoid hemorrhage without hydrocephalus, in whom a right choroidal aneurysm was early excluded by endovascular coil insertion. Intracranial pressure (PIC) and cerebral oxygenation (PtiO2) sensors for neuromonitoring were installed due to a persistent comatose state. From the 3rd day, neuromonitoring became altered. CT angiography and cerebral angiography showed severe proximal and distal vasospasm (VE) of the middle (ACM) and anterior (ACA) right cerebral arteries. VE was treated with angioplasty and intravenous nimodipine. Forty eight hours later, despite hemodynamic maximization, neuromonitoring became altered again, mainly explained by a decrease in PtiO2 below 15 mmHg. A severe VE in ACM and right ACA was confirmed by angiography. Given the presence of an early and recurrent VE, which was associated with a decrease in cerebral oxygenation, internal carotid micro-catheters for continuous nimodipine infusion were installed. This therapy maintained a normal neuromonitoring for 15 days. During this period, attempts were done to decrease or discontinue the infusion, but the patient presented parallel falls of cerebral oxygenation or decreased cerebral perfusion observed with perfusion CT, interpreted as persistent VE. Finally, the infusion was stopped at day 15 without significant complication. We conclude that intra-arterial nimodipine continuous infusion in refractory VE can be useful and safe in selected patients. Multimodal neuromonitoring is essential.

Use of Three-dimensional Printing in Orthopaedic Surgical Planning.

BACKGROUND: Three-dimensional (3D) printing is a technique based on overlapping layers of a material (eg, plastic, clay, and metal). The widespread implementation of 3D printers has resulted in a notable increase in use. Fields such as construction, engineering, and medicine benefit from this technique. AIM: The use of 3D printed scale models permits better surgical planning and results. METHODS: The models were created based on CT images of seven patients (age range, 5 to 61 years) with different pathologies who were candidates for surgery. RESULTS: Surgical time decreased as a result of detailed surgical planning with printed models. This technique also was associated with a decrease in bleeding, a reduction in the amount of anesthesia required, and greater precision. In some patients, a change in surgical strategy was noted, thus allowing for a reduction in the number of surgeries and the aggressiveness of surgery. Finally, the preoperative practice (virtual and physical osteotomies using cutting tools) that was performed in two cases allowed the surgeon to evaluate the different approach alternatives and establish the best strategy. CONCLUSIONS: The use of 3D-printed anatomic models has improved surgical planning, especially for patients in whom the conventional techniques are insufficient for establishing a proper strategy. The extra information provided by 3D-printed models can lead to a better intervention strategy, which is beneficial for patients because it decreases the risks, procedure times, and recovery times.

Study of Resting-State Functional Connectivity Networks Using EEG Electrodes Position As Seed.

Electroencephalography (EEG) is the standard diagnosis method for a wide variety of diseases such as epilepsy, sleep disorders, encephalopathies, and coma, among others. Resting-state functional magnetic resonance (rs-fMRI) is currently a technique used in research in both healthy individuals as well as patients. EEG and fMRI are procedures used to obtain direct and indirect measurements of brain neural activity: EEG measures the electrical activity of the brain using electrodes placed on the scalp, and fMRI detects the changes in blood oxygenation that occur in response to neural activity. EEG has a high temporal resolution and low spatial resolution, while fMRI has high spatial resolution and low temporal resolution. Thus, the combination of EEG with rs-fMRI using different methods could be very useful for research and clinical applications. In this article, we describe and show the results of a new methodology for processing rs-fMRI using seeds positioned according to the 10-10 EEG standard. We analyze the functional connectivity and adjacency matrices obtained using 65 seeds based on 10-10 EEG scheme and 21 seeds based on 10-20 EEG. Connectivity networks are created using each 10-20 EEG seeds and are analyzed by comparisons to the seven networks that have been found in recent studies. The proposed method captures high correlation between contralateral seeds, ipsilateral and contralateral occipital seeds, and some in the frontal lobe.

Mobile Device Applications for the Visualization of Functional Connectivity Networks and EEG Electrodes: iBraiN and iBraiNEEG.

Multiple functional MRI (fMRI)-based functional connectivity networks were obtained by Yeo et al. (2011), and the visualization of these complex networks is a difficult task. Also, the combination of functional connectivity networks determined by fMRI with electroencephalography (EEG) data could be a very useful tool. Mobile devices are becoming increasingly common among users, and for this reason, we describe here two applications for Android and iOS mobile devices: one that shows in an interactive way the seven Yeo functional connectivity networks, and another application that shows the relative position of 10-20 EEG electrodes with Yeo's seven functional connectivity networks.

Comparative Neuroregenerative Effects of C-Phycocyanin and IFN-Beta in a Model of Multiple Sclerosis in Mice.

Multiple Sclerosis (MS) therapies approved so far are unable to effectively reverse the chronic phase of the disease or improve the remyelination process. Here our aim is to evaluate the effects of C-Phycocyanin (C-Pc), a biliprotein from Spirulina platensis with anti-oxidant, anti-inflammatory and cytoprotective properties, in a chronic model of experimental autoimmune encephalomyelitis (EAE) in mice. C-Pc (2, 4 or 8 mg/kg i.p.) or IFN-beta (2000 IU, s.c.) was administered daily once a day or every other day, respectively, starting at disease onset, which differ among EAE mice between 11 and 15 days postinduction. Histological and immunohistochemistry (anti-Mac-3, anti-CD3 and anti-APP) assessments were performed in spinal cord in the postinduction time. Global gene expression in the brain was analyzed with the Illumina Mouse WG-6_V2 BeadChip microarray and the expression of particular genes, assessed by qPCR using the Fast SYBR Green RT-PCR Master Mix. Oxidative stress parameters (malondialdehyde, peroxidation potential, CAT/SOD ratio and GSH) were determined spectrophoto-metrically. Results showed that C-Pc ameliorates the clinical deterioration of animals, an effect that expresses the reduction of the inflammatory infiltrates invading the spinal cord tissue, the axonal preservation and the down-regulation of IL-17 expression in brain tissue and serum. C-Pc and IFN-beta improved the redox status in mice subjected to EAE, while microarray analysis showed that both treatments shared a common subset of differentially expressed genes, although they also differentially modulated another subset of genes. Specifically, C-Pc mainly modulated the expression of genes related to remyelination, gliogenesis and axon-glia processes. Taken together, our results indicate that C-Pc has significant therapeutic effects against EAE, mediated by the dynamic regulation of multiple biological processes.

Stereoscopic three-dimensional visualization applied to multimodal brain images: clinical applications and a functional connectivity atlas.

Effective visualization is central to the exploration and comprehension of brain imaging data. While MRI data are acquired in three-dimensional space, the methods for visualizing such data have rarely taken advantage of three-dimensional stereoscopic technologies. We present here results of stereoscopic visualization of clinical data, as well as an atlas of whole-brain functional connectivity. In comparison with traditional 3D rendering techniques, we demonstrate the utility of stereoscopic visualizations to provide an intuitive description of the exact location and the relative sizes of various brain landmarks, structures and lesions. In the case of resting state fMRI, stereoscopic 3D visualization facilitated comprehension of the anatomical position of complex large-scale functional connectivity patterns. Overall, stereoscopic visualization improves the intuitive visual comprehension of image contents, and brings increased dimensionality to visualization of traditional MRI data, as well as patterns of functional connectivity.

Phycocyanobilin promotes PC12 cell survival and modulates immune and inflammatory genes and oxidative stress markers in acute cerebral hypoperfusion in rats.

Since the inflammatory response and oxidative stress are involved in the stroke cascade, we evaluated here the effects of Phycocyanobilin (PCB, the C-Phycocyanin linked tetrapyrrole) on PC12 cell survival, the gene expression and the oxidative status of hypoperfused rat brain. After the permanent bilateral common carotid arteries occlusion (BCCAo), the animals were treated with saline or PCB, taking samples 24h post-surgery. Global gene expression was analyzed with GeneChip Rat Gene ST 1.1 from Affymetrix; the expression of particular genes was assessed by the Fast SYBR Green RT-PCR Master Mix and Bioplex methods; and redox markers (MDA, PP, CAT, SOD) were evaluated spectrophotometrically. The PCB treatment prevented the H2O2 and glutamate induced PC12 cell injury assessed by the MTT assay, and modulated 190 genes (93 up- and 97 down-regulated) associated to several immunological and inflammatory processes in BCCAo rats. Furthermore, PCB positively modulated 19 genes mostly related to a detrimental pro-inflammatory environment and counteracted the oxidative imbalance in the treated BCCAo animals. Our results support the view of an effective influence of PCB on major inflammatory mediators in acute cerebral hypoperfusion. These results suggest that PCB has a potential to be a treatment for ischemic stroke for which further studies are needed.

Incidence of lobar and non-lobar spontaneous intracerebral haemorrhage in a predominantly Hispanic-Mestizo population--the PISCIS stroke project: a community-based prospective study in Iquique, Chile.

BACKGROUND: The incidence of intracerebral haemorrhage (ICH) in Hispanics is high, especially of non-lobar ICH. Our aim was to ascertain prospectively the incidence of first-ever spontaneous ICH (SICH) stratified by localisation in a Hispanic-Mestizo population of the north of Chile. METHODS: Between July 2000 and June 2002 all possible cases of ICH were ascertained from multiple overlapping sources. The cases were allocated according to localisation. Those with vascular malformations or non-identifiable localisations were excluded. RESULTS: We identified a total of 69 cases of first-ever ICH. Of these, 64 (92.7%) had SICH, of which we allocated 58 cases (84%) to non-lobar or lobar localisation. The mean age was 57.3 +/- 17 years, and 62.3% of the subjects were male. The age-adjusted incidence rates were 13.8 (non-lobar) and 4.9 (lobar) per 100,000 person-years. Non-lobar SICH was more frequent in young males and lobar SICH in older women. The non-lobar-to-lobar ratio was similar to previous findings in Hispanics. Hypertension was more frequent in non-lobar SICH and in diabetes, heavy drinking and antithrombotic use in lobar SICH, but in none significantly. There was no association between localisation and prognosis. CONCLUSIONS: The incidence of non-lobar SICH was high, but lower than in most non-white populations. This lower incidence could be due to a lower population prevalence of risk factors, a higher socioeconomic level in this population, or chance.

Blood flow dynamics in patient-specific cerebral aneurysm models: the relationship between wall shear stress and aneurysm area index.

Hemodynamics plays an important role in the progression and rupture of cerebral aneurysms. The temporal and spatial variations in wall shear stress (WSS) within the aneurysmal sac are hypothesized to be correlated with the growth and rupture of the aneurysm. The current work describes the blood flow dynamics in 34 patient-specific models of saccular aneurysms located in the region of the anterior and posterior circulation of the circle of Willis. The models were obtained from three-dimensional rotational angiography image data and blood flow dynamics was studied under a physiologically representative waveform of inflow. The three-dimensional continuity and momentum equations for unsteady laminar flow were solved with commercial software using non-structured fine grid sizes. The vortex structure, the wall pressure, and the WSS showed large variations, depending on the morphology of the artery, size of the aneurysm, and form. A correlation existed between the mean WSS on the aneurysmal sac for lateral unruptured and ruptured aneurysms with an aneurysm surface index, which is defined as the ratio between the aneurysm area and the artery area at model inlet, respectively.

Incidence, case-fatality rate, and prognosis of ischaemic stroke subtypes in a predominantly Hispanic-Mestizo population in Iquique, Chile (PISCIS project): a community-based incidence study.

BACKGROUND: Incidence of ischaemic stroke subtypes, classified by cause, seems to vary between communities. We aimed to prospectively ascertain the incidence of first-ever ischaemic stroke in a predominantly Hispanic-Mestizo population in the northern desertic region of Chile. METHODS: Between July, 2000, and June, 2002, all patients with possible stroke or transient ischaemic attacks were identified from multiple overlapping sources and were rapidly assessed by two field neurologists. All identified patients were diagnosed by at least two stroke neurologists according to Trial of Org 10172 in Acute Stroke Treatment (TOAST) definitions and were followed up at 6 months. Annual incidence rates were age adjusted to WHO, European, and US populations by the direct method to allow comparisons. FINDINGS: A total of 239 ischaemic strokes were identified, of which 185 (77%) were first-ever cases. 151 (82%) patients were hospitalised, of whom only 70 (38%) were assessed within 6 h of symptom onset. The mean age of patients was 66.4 years (SD 14.9) and 56% were men. The crude annual incidence rates (per 100 000) according to stroke subtype were: cardioembolic, 9.3; large-artery disease, 2.0; small-vessel disease, 15.8; other determined cause, 0.2; and undetermined cause, 17.4. Hypertension was the most common cardiovascular risk factor in all subtypes and atrial fibrillation was the most common cause of cardioembolic stroke. Case fatality at 30 days was highest in cardioembolic strokes (28%) and lowest in small-vessel disease (0%). Dependency or death at 6 months was also highest in cardioembolic strokes (62%) and lowest in small-vessel disease (21%). INTERPRETATION: Incidence and prognosis of small vessel and cardioembolic infarction was similar to that in other populations and incidence of large-artery atherothrombotic infarction was lower than in most previous reports. Hypertension and atrial fibrillation were the most common risk factor and cause, respectively, of ischemic stroke in this population. These findings should help the national stroke programme in the prevention of cardioembolic stroke, increase access to specialists and acute brain imaging and vascular studies, and improve stroke care.